Improvement in the manufacture of abtificial stone



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WILLIAM K. BOYLE,

O F BROOKVILLE, MARYLAND.

Letters Patent No. 82,202, dated September 15, 186B; antcduterl September 7, 1308.

IMPROVEMENT IN THE MANUFACTURE OI ARTIFICIAL STONE.

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TO ALL WHOM IT MAY CONCERN:

Be it known that 1, WILLIAM K. BOYLE, oi Broolrville, county of Montgomery, and State of Maryland, have invented a new and useful Improvement in the Manufacture of Artificial Stone; and I do hereby declare the following to be a full, clear, and distinct description of the ingredients, and of the process for preparing and compounding the same.

My invention relates to :he formation of artificial stone by the use of the soluble silicate of potash, in combinntion witl sand, gravel, or any earthy material, for forming the mass or body of the stone, an subsequently Submitting the mass t as formed to the action of a hoistj ution oi' tho nitra te o filim e, whereby, by virtue of the chemical aiiinities, the insoluble silicat d of liin oisproduced, constituting the cementing property, the soluble oi: ppiaslr remairiing in the bath in which the chemical change has taken place, which solution, by evaporation, can be utilised, forming, as it does, the nitrate of potash, orgaltpetre.

Process.

Mix intimately with well-dried sand, proverb clay, earth, or any insoluble substance, including ninerls reduced to a finely-pulverized state, a sufficient quantity oi the soluble silicateoi potash, in the semi-fluid form, say 1,500 or 2,000 specific gravity, to form a plastic mass. The mixing of these ingredients may be by hand or appropriate machinery. As a general rule, the quant-it'resshoul l be about in proportion of one part o il i; cate of otash to six or eight parts oi' sand, ela ,grnvel, &c. A small quantity of fine hvdrate of lime or common slaEoil lime, or any form of the carbonate of lime, may be mixed with the compound, that every crevice may he eil'cctively filled. The mass is then pressed into moulds, of any form which may be desired, said moulds being made of plaster of Paris, wood, iron, or any other suitable material.

Then the mass, in the mould or moulds, is to be immersed in a hot or boilin splutiongipitrate of lime, when a chemical interchange, by virtue of chemical aiiinities, takes place, the nitric acid oi the solulile nitrate of lime having a greater ailinity for the potash than for the lime, the insoluble silicate of lime forms the cementing property, while the soluble nitrate of potash is held in solution.

After this boiline is over, which may be continued until the chemical action has become perfect, which requires alongcr or shorter period, according to the size of the mass, the stone still in the mould is to be immersed in boiling water until the nitrate of potash is dissolved, when it may be removed from the mould, and exposed to a gentle heat until dry, after'which it is ready for use.

The boiling water, saturated with nitrate of potash, is then evaporated to dryness, and the residue will be found to be nitrate of potash, or saltpetre, having a considerable commercial value, by which the cost of manufncturing the stone is very m h reduced.

In order to make the stone entirely impervious to water, the surface, after the boiling process is completed, may be washed with a solptiop of silieatg cipgtash and the nitrate of lime, and again washed in water.

Stone thus formed will withstand the ordinary atmospheric tests, and will not be liable to injury from acids, having a hardness and durability, nearly if not quite equal to granite.

What I claim as my improvement and discovery, and desire to secure by Letters Patent, is-

The herein-described process of manufacturing artificial stone, by means of which the insoluble silicate of lime is formed, by the double decomposition of the silicate of potash and nitrate of lime, substlntially as herein set forth and described.

And, as a secondary resnltfI claim the utilization oi the nitrate of potash, l8 a waste material, in the nnnufacture of artificial stone, as herein set forth and described.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

WM. K. BOYLE.

Witnesses:

.Joun. D. Bnoon,

J0me S. Hosmzsospnsn. 

